Swiveled cutter hobber



Jan. 15, 1929 w. F. ZIMMERMANN SWIVELED CUTTER HOBBER Filed Dec. 11, 1926 5 Sheets-Sheet 1 avwemtoz 33x3 a'ttOZ/MQ/ta I Jan. 15, 1929. 1,699,264

w. F. ZIMMERMANN SWIVELED CUTTER HOBBER Fil6d D80- 11, 1926 5 Sheets-Sheet 2 avwamboi 35 fitter/neg;

Jan. 15, 1929. 1,699,264

w. F. ZIMMERMANN SWIVELED CUTTER HOBBER Filed Dec. 11. 1926 s Sheets-Sheet Qvwemtoz wzLumir-fi H i immune won Patented Jim. 15, 1929.

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This inventionzis -a :further advance in my progressive development 6f balanced drive hobbers along the line initiated by my earlier Patent N 0. 1,472,767 and subsequent ly carried "forward" by mylaiter 'Petent No. 1,603,258. In the earlier case, the balance was attained in What might termed a single purposemachine embodyingtwo index gears, and-in thelater instance it was uttainedin a machine ofgrewter range in which the compound index; gears embodied four distinct gears. In each case, the genillustrated a shit'table eral organization Work-carrier.

The present *advamce aims to attain (through a' condensed andsimplifiedstructure) theadvantagesofa; balanced drive of adequate range yet containingii but three index gears, as Welles thendvantagesffiowing from a Work-carrier in the nature ofnn anvil as distinguished from a shifteble Y workcurriage. Each of "these Characteristics Inutually cooperate towards reducing Vibration or chatter, the bete noire of production machines in the case of the" balanced drive by m'oicling preponderating sources of backlash between the: serial elements of the tooldriving and the work-"driVing transmissions, respectively, and in the case-of the anvill'ike work-.supporflby presenting the greatest: practicable rigidity in opposition" to the hammering impacts en the successively acting cutter-blades.

By making :1 shifteble work-carrier sufficiently massive, its "responsive vibrations may become unobjectionable, bub-an undue increase in the gross Weight of themacl1ine is thereby necessitated. But by making the work-carrier non-shiftebleend in effect integrzil with the bed, the-normidrhass of the bed becomes eveilableasnn anvil (and other conveniences ere had) and all Without eddinn metzil to the carriage.

In departing from convention H as aforesaid, this inventiontekesedvantage otthe fact thatthe stanchion is normzr llyheavy and massive. It is now proposed remake it shiftable, (insteetd of the workcurrier) for i-swrvnnnn CUTTER Bonner;

Applicationflledhecember 11, 1926'. j Seria1.1o.154,054.

:Work spindle a a; OFJHAPLEWOOI), NEWHJERSEYQASSTGNIGRTTOAGOUIDD & NEWARK, IEWIERSEY, Ar ,CORPGRLATION i :0]? -NEWI JERSEY the dual, purpose of obtaining adjustment needed and at the-same time procuring the 60 eflect =of ashiftz'lble anvil. Thisflfurther more, 1s accomplished 5 by reorganization of the transmission system in such a manner that a condensed balanced-drive is provided for propelling the spindlesend=for-nccom modating the body-shift of "the stanchion.

To illustrate how i the iforegoingubharacteristics may be mechanicellyembodiedin a coordinated 1 mechanism, drawings are annexed and, in these; Fig.1-is:aside*elevetion of a hobbi-ng-meelnne-show'in e f'uzed "Work spin'dleqand*e shifteblestwnc ion supporting a' hob-carrying heedslidhble thereon all, in combination with -a-compaflible simplified balanced ldrive comprising but three index gears. FigNQqisaskeletonmf tlie belanced drive transmission system for performing the l various movements #01: the orking it and 1 positioning elements of l the machine. *FigSIZSnndA arereawand front 10 end elevetionsy respectively, en the machine showin further "details of the mzmner of combining the balanced "drive with the major frame-elements of the mabhine.

ThebedA, in this embodiment,is elongated and positioned horizontally en'd provides a forward working region in-Which the work spindle is 'directly journhled sobas to occupy 1 a fixed position, A and the bed fprovides also a rear meehanism-supportin ugi0n-0n which the stanchion is 'sli ebly mounted. The "Work spindle W is shown journeled in fixed bearings A" and itextends downwardly into the interior of the be'das indicated 'by W and, et its lower-end, carries worm wheel W by which it is driven. The portion of the bed that housesfthe worm w-heel W isappropriately enlarged to contain that wheel end, inasmuch as "the Wheel occupies a fixed position inspece," the bed edm-its of being ribbedend reinforced closely to the wheel and thus made very rigid as will be understood *without illustration. It is ,noteworth that 1 by thus; giving the Iliad positionet the forward 08 end of the bed, it is at allitimes quickly accessible to the user and it is not at one time further from the end of the bed than at another as often happens when the work spindle is shiftable in position. The mounting of the spindle is accomplished in a very solid manner with the object of realizing the effect of an anvil so that it virtually supports the work substantially as solidly as though it was clamped to the bed itself and, in consequence, the tendency to vibrate and chatter is reduced to a minimum.

The stanchion S is in the nature of a heavy box-like casting which is provided with slidewa-ys S and S at right angles to one another; the slideways S resting on the slideways S provided by the surface of the bed and arranged to permit the heavy stanchion to he slid towards and away from the axis of the work spindle for the purpose of determining the diameter of the gear G to be cut by the machine. The purpose of the transverse slideways S is to support and guide a head H which is thus shiftable in parallelism with the axis of the work-spindle so that the cutter or hob (which is carried by the head) may in the course of the feeding movement cut the teeth of the gear G. It will be understood that this head H is suitably gibbed to the slideways S and, in order to counterbalance the weight of the head H, a counterweight H may be arranged to rise and descend in an appropriate well provided by the stanchion S; conventional ropes and pulleys H and H being provided as will be understood.

It is to be noted that the stanchion, being heavy and massive, is in effect a part of the solid bed itself because, when clamped down to that bed, it becomes very solid therewith owing to the action of the clamps augmented by the weight of the stanchion and by reason of the fact that the base of the stanchion S is very extensive so as to resist effectively such overturning forces as result from the pressure of the hob against the work during the tooling operation. It will likewise be noted that, in cutting spur gears, the stanchion requires to be shifted only when a change is to be made in the diameter of the spur gears being out (which ordinarily would be quite infrequent) and it will also be noted that the shifting of the stanchion does not reduce the facility of access of the user to the work spindle and does not interpose obstructions when brought closer to that spindle. It will also be noted that the slideways S at the base of the stanchion runs to a region substantially underlying the head H so that this construction avoids the objectionable overhang which is necessitated whenever the work spindle is mounted on a carriage which slides on the bed.

The simplified transmission system for rotatin both the work spindle and the hob, and or progressively feeding the head H,

and for shifting the position of the stanchion S, and for varying the rates of rotations and for shifting the parts quickly or slowly as the case may be, will now be described.

This transmission is in the nature of a balanced drive and comprehends an intermediate splined shaft X and two main transmission shafts Y and Z: the hob-driving shaft Y being also splined. These two shafts are disposed at right angles and the splined intermediateshaft is parallel with one of them; the latter being in this embodiment the non-splined shaft that communicates motion to the work spindle. The intermediate shaft receives the power in the first instance; this bein accomplished by the power-line consisting of a pulley P or other prime-mover, the power shaft P and appropriate gears such, for example, as the two spur gears l? and P and the two angle gears P and P The hob-driving splined transmission shaft Y is journaled in the shiftable stanchion so as bodily to travel therewith in a direction parallel. with the intermediate shaft and, at its lower end, it is provided with an angle gear 2 which meshes with a shiftable angle gear w which splined to the intermediate shaft X. With respect to the hob-spindle, the head 3 has a suitable bracket 33 which journals the angle'gear and causes it to slide on the shaft Y (to which it is splined) and be kept in true mesh with the angle gear 7 of the unit 1 c which is likewise journaled on the head 3 transversely to the shaft Y; the axis of the unit y cbeing utilized as an off-set center of swivel for the hob bearing 30. A worm c on the hob spindle meshes with the worm 6. It may be noted here that, since that center of swivel is off-set, the hob may not be swiveled through such a wide range of angles as if the center of swivel had been coincided with the center of the hob and thus the range of the machine is to that extentrestricted; but the advantage is that the construction is greatly simplified and requires precisely the two gears extra (one tooth contact) required to balance the drive in combination with the same number of two extra pairs of inter-meshing tooth coir tacts provided respectively by the index change gears :0 I and I.2 employed extra change gears for materially extending the range of speeds of the work relative to the cutter. In other words, the employment of the three change gears 03:, I and (yielding two tooth contacts) is made possible without disturbing the balance of the drive of the spindles, by using also the two extra gears 50 and y, (yielding one tooth contact) and conversely and thus not only is the speed range extended through the three change gears but the hob may be disposed at various lncldental angles within a considerable range from nefixeam predetermined base- 1, angle. These! three "gears: provide two pairs Moi tooth contact,- i. e., between earsxt'tand I,

:andwbetween, I; and 2?. This aEords-six pairs at tooth contacts; three being used to transma: tliegmotion from the connection with the -pairs wy, wyiand e0. i llheother set of three tooth-contacts is provided by the gear pairsnw l, Le end Z'WV :The other non-splined, transmission shaft is journaled in the bed of the machine and has: aworm: zflafiiied 'thereto for driving the spindleiW through the worn1wheel V To start the machine, the power lever B is actuated. This shiftsthe collar 8 and slides :a long key 9 (which is translatably countersunk in; theshaft" P) and this key actuates :asuitableclutch (not-shown) between the prime-mover i P Land the shaft P. The transmission elements previously "described are then maintained inmotion by the power imparted to the intermediate shaft and the cntterand thework are botlrrevolved at the "relative rate determined by the three change gears 2 I andw To? manually shift: the stanchlon a hand wheel V (provided with graduations or "micrometer adjustments) is affixed to a shaftthat carries :an angle gear V which meshes with :an angle gear V? which is splined'totthe screw S and enables it to be turned by'hand. That screw is @appropri ately jonrnaled and threaded,respectively,

between-afixed part of the frame and a part shiftable with the stanchion. The above described manual means enables the user very readily tobring the stanchionto any desired position with respect toithe workspindle 1 tor cutting s ur-gears.

1T0? feed the cutter cad; the parts 'willbe in the positions andrela-tions shown best by Fig. 2 The feeding! motion isconveyed by a transmission consisting ot'ian; angle gear lmounted on theshaft Z andmeshing with @an angle gear QARiliXBClWOWhG shaft3. A worm 4 on that shaft drives a Worm-wheel which turns the shaft 6 and, through appropriate changeagears designated: generally by 7, the gears r is driven an'd'this gearis arranged to drive the shaftwF, as for example, by being aflixed to a sleeve o-"which is loosely mounted on: the shafnF 'but adapted to be. connected thereto'by" the clutch-teeth r by bodily shiftinguthe sleeve r. Angle gearsF and F transmit themo'tion from the shaftrl? to the shafts]? which isrjournaleid in the stanchionandpat its upper end,

has a gear F which meshes with a gearF which is a unit with a nut that turns about the non rotatable feed-screw F. That feed-screw is aflixed to the head H and is caused to move up or .idowmasr the case may be,1by the ronested up as described.

tating nut :and, in this manner; the 5 cutter wjournaled on the head is caused to feed downwardly whenever the parts are con- Vithout further in analysis, the foregoing will so fully:revealthegist of this invention that others can, by applying current knowledge, readily adapt it for various ntilizationsby retaining one or morewof the .featuresethat, fro nthe standpoint ofthei' prior art, fairly constitute essential chartLCtGl'lStlCS 0t either the generic or specific "aspects of :Lthis invention and, theretore,

such adaptations should be; and are intended to be comprehended within themeaning and range of equivalency of the following claims.

Having thus revealed this invention, I clainras new and desire to secure the following rombinations and elements, or equivalents thereof," by Letters Patent ofthe United States: l

1. A hobbing-machine combiningqa hobsupporting spindle; means for shiftingsaid spindle laterally in either one of two transverse directions; a work-supportings indie; a transmission connecting said spind es and consisting of but three shaftsandgears providing sixpairs of tooth-contacts; a primemover geared directly toone of the inter mediate parts whereby the power 'for 'drivingeach of said spindles will be transmitted by but three tooth contacts, one of the gears used for propelling the laterally shiftable hob supporting' spindle having its axis ex tending in a direction transverse to the axis of said Work-supporting spindle and being splined tocthe shaft on which it is mounted; and means fol-effecting a translation of said hob-supporting spindle in directions parallel with and transverse to the work-supporting spindle. y a

a 2. A balanced-drive bobbing-machine comprising a bed, a relativelyheavy stanchion shit'tably supported thereon; a work'supporting spindle non-shiftably journaled 1n said bed near one end thereof; a splined shaft and a parallel transmission shaft, each journaled on said bed transversely to said spindle; three serially arranged change gears connecting said two shaft-s; a splined transmission shaft journaled on said stanchion parallel with saidspindle; a head slidable onsaid stanchion; a hob-supporting spindle swivelablymounted on saidhcad; gears providing two pairs of tooth-contacts connecting said hob spindle with said splined transmission shaft, one of said gears being splined to said shaft; a pairof gears connecting said stanchion shaft-tosaid firstmentioned splined shaft, one of saidgears being splined thereto; and a pair of gears prising a bed; a relatively heavy stanchion shiftably supported thereon; a work-supporting spindle non-shiftably journaled in said bed near one end thereof; a splined transmission shaft journaled on said stanchion parallel with said spindle; an intermediate splined shaft and a parallel transmission shaft, each journaled on said bed transversely to said spindle; change gears providing two pairs of tooth contacts connecting said two shafts; a head slidable on said stanchion; a hob-supporting spindle mounted on said head; gears providing two pairs of tooth contacts connecting said hob spindle with said splined transmission shaft one of said gears being splined to said shaft; a pair of gears connecting said splined shaft to said intermediate splined shaft, one of said gears being splined to said intermediate shaft; and a pair of gears connecting said parallel transmission shaft with said nonshiftable work spindle.

i. A balanced drive bobbing-machine combining a bed having a slidable stanchion; a head slidable thereon; a hob supporting spindle swivelly mounted on said head; a carriage fixed on said bed; a work-supporting spindle on said carriage; a three-shaft transmission connecting said spindles. two of said shafts being arranged parallel to each other and one of said parallel shafts being splined traversely to said work-supporting spindle, the adjacent ends of said two parallel shafts being connected by change-gears providing two pairs of tooth contacts, the third shaft of said transmission being splined and arranged transversely to the other spindle and being connected by two pairs of gears to saidother spindle and, at its other end, being connected by a pair of gears directly to the splined one of said two parallel shafts, the other of said parallel shafts being connected to the workspindle by a pair of gears; a prime-mover geared directly to the intermediate splined shaft whereby power will be derived from its respective ends for driving said spindlepropeller shafts; and means for effecting a progressive feed of said head in a direction parallel with the work-supporting spindle.

5. A bobbing-machine comprising a bed; a work-supporting spindle nonshiftably journaled in said. bed near one end thereof; a relatively heavy stanchion shiftably sup ported thereon; a head slidable on said stanchion; a mounting sw velly affixed to said slidable head; a hob-supporting spindle journaled in said mounting to swivel therewith; a worm-wheel. on the hob-supporting spindle; a worm-wheelaiiixed to the worksupporting spindle; a transmission for driving said spindles and terminating at its ends in worms meshing respectively with said worm-Wheels; and means for imparting motion to said transmission.

6. A balanced-drive hobbing-machine comprising a bed; a relatively heavy stanchion mounted thereon; a work supporting spindle supported by said bed; a splined transmission shaft journaled on said stanchion parallel with said work-supporting spindle; an intermediate shaft and a parallel trans mission shaft, each journaled on said bed transversely to said worlcsupporting spindle; change gears providing two pairs of tooth contacts connecting said two parallel shafts; a head slidable on said stanchion; a hob-supporting spindle mounted on said head; a first worm and worm-wheel, the worm-wheel being afiixed to said hob spindle; a pair of gears connecting said shaft with said worm; a pair of gears connecting said splined shaft to said intermediate shaft; and a second worm and worm-wheel connecting said parallel transmission shaft with said work-spindle, the worm being mounted directly on said shaft and the worm-wheel being on said work-spindle.

7. A balanceddrive bobbing-machine com: prising a bed; a relatively heavy stanchion shiftably supporting thereon; a worlcsupporting spindle non-shiftably journaled in said bed near one end thereof; a wormwheel on said spindle; a splined transmission shaft journaled on said stanchion parallel with said work-supporting spindle; an intermediate splined shaft and a parallel transmission shaft, each journaled on said bed transversely to said work-supporting spindle; change gears providing two pairs of tooth contacts connecting said two shafts; a head slidable on said stanchion; a hobsupporting spindle mounted on said head; a worm-wheel on said spindle; a worm and a pair of gears connecting said hobspindle with said first-mentioned spliced trans1nission shaft, one of said gears being splined to said shaft; a pair of gears connecting said first-mentioned splined shaft to said intermediate splined shaft, one of said gears being splined to said intermediate shaft: and a worm and worm-whee]. connecting said parallel transmission shaft with said nonshiftable work spindle.

8. A balanced drive hobbinganachine combining a bed having a slidable stanchion; a head slidable thereon; a hob supporting spindle swivelly mounted on said head; a carriage fired on said bed; a worksupporting spindle on said carriage; a three-shaft transmission connecting said spindles, two of said shafts being journalcd in parallelism on said bed and one of said. parallel shafts being splined, the adjacent ends of said two parallel shaft-s being connectcd by change-gears providing two pairs of tooth contacts, the third shaft of said transmission being splined and arranged transversely to and connected with the splined one of said two parallel shafts by a pair of gears; a prime-mover geared directly to the intermediate splined shaft whereby power will be derived from its respective ends for driving said spindlepropelling shafts; a Worm and Worm-Wheel directly connecting the work-spind1e with the non-splined one of said parallel shafts;

a pair of gears driven by the third splined transmission shaft; and a worm and Worm- WhQGI for driving said hob-spindle by 10 motion derived from said pair of gears.

In Witness whereof, I have hereunto subscribed my name.

WILLIAM F. ZIMMERMANN. 

